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permanent heat, of moderate humidity, and of the variety of 

 the soil. The more, on the contrary, that we approach the 

 boundary where begins the reign of everlasting ice and 

 snows, whether we proceed towards the poles, or ascend to 

 the heights of lofty mountains, where the diminution of ca- 

 loric produces similar phenomena, the greater is the decrease 

 of plants and of insects. Thus Otho Fabricius, who has 

 published a good Fauna of Greenland, enumerates but 468 

 species of animals altogether, and the number of those of 

 insects, including, according to the Linnsean system, the 

 Crustacea and arachnida, amounts only to 110. The cata- 

 logue of this naturalist may perhaps be not complete ; but 

 even so, we are justified in believing that the number of in- 

 sects in that country must be extremely limited. But when 

 we come to the desolate domains of eternal winter, life totally 

 disappears, and the productive force of nature is at an end. 

 The plains in the neighbourhood of the poles, the very 

 elevated regions of the mountains of the temperate and 

 torid zones, covered with perpetual snow, exhibit, in this 

 respect, the same state of inertia. These mountains, consi- 

 dered with regard to the animals and vegetables which are 

 peculiar to them, form gradually, and by superposition, 

 particular climates, whose temperature and productions are 

 similar to those of the plains of the most northern countries. 

 Thus we find that the Alps are the habitation of many species 

 of insects which are again to be found only in the north of 

 Europe. The prionus depsarius, which had long been sup- 

 posed to belong to no other country but Sweden, has been 

 discovered in the mountains of Switzerland M. Latreille 

 has found at Cantal the lycus 7ninutus, which used to be 

 considered peculiar to the most northern provinces of Eu- 

 rope. The butterfly named Apollo by Linnaeus, very com- 

 mon in the fields and gardens of Upsal, as well as in other 

 parts of Sweden, is found in France only on mountains 



